442 Sot Springs, and other Natural Features of the Pyrenees. 



which the name is derived), in Ariege, numbers no less than 

 eighty-four of these hot springs, the hottest and most copious 

 of any in the Pyrenees. A few, like those at Bagneres de 

 Bigorre, are purely saline. The majority are impregnated with 

 sulphuretted hydrogen, a gas easily decomposed by contact 

 with the air, and depositing a precipitate of sulphur, called 

 ce baregine," in open channels near their sources. The spring 

 at Moudang contains protosulphate of iron, by which the waters 

 preserve their sulphurous character for some time ; and the 

 waters of this spring and of a few others are exported. 



The average temperature of thermal springs in the Pyre- 

 nees is more than 100° Fahrenheit, well adapted for therapeutic 

 purposes in every variety of baths, douches, etc. The vessels 

 for these baths are generally made of the marble of the country. 

 That the hot springs were known to the early Romans, and 

 were by them used for this purpose, is apparent from recent 

 excavations at Bagneres de Bigorre, where baths have been 

 discovered more extensive than any there existing at the pre- 

 sent day. The question, if these thermal springs have preserved 

 a constant temperature after the lapse of so many centuries, is 

 one of some interest in connection with the geology of the 

 chain. As long ago as the year 1.835, Professor Forbes, of 

 Edinburgh, specially examined their temperatures with a view 

 to discover if any variations could be traced in a moderate 

 number of years. In the interval now elapsed, of thirty 

 years, many careful observations have been made, but no per- 

 manent variations have been brought to light. The most 

 recent series of observations w T ith which we are acquainted is 

 that by Dr. Scoresby Jackson, in August, 1863, described in 

 vol. xxiii., part iii., of the Transactions of the Royal Society of 

 Edinburgh. By Professor Forbes the waters were examined, at 

 their source, or " griffon," as it is termed, of the spring, where 

 the waters issue from the rock. They are conducted thence 

 by means of various channels to the different parts of the 

 thermal establishments, as douches, baths, etc., and to the 

 " buvettes," which are the public fountains, where persons 

 ordered for their health to drink the waters are supplied. At 

 this spot a thermometer placed for a few minutes under the 

 constantly-flowing stream, records the temperature of the 

 water at the buvettes ; but not by any means its temperature 

 at the griffon, which is often a considerable distance from the 

 buvette. As the rock is from time to time explored, and the 

 buildings are improved, alterations at both sites are occa- 

 sionally made. The constancy of temperature at the buvette 

 is, however, in general, as remarkable as at the griffon of the 

 spring itself. In Dr. Scoresby Jackson's experiments the 

 temperatures were recorded at both places. At whatever point 



